Experts tag last shark of year off Cape

The fourth, and possibly last, great white shark to be fitted with a tracking device this year was tagged Thursday afternoon by a team of state researchers and fishermen just outside the inlet to Chatham Harbor.

CHATHAM — The fourth, and possibly last, great white shark to be fitted with a tracking device this year was tagged Thursday afternoon by a team of state researchers and fishermen just outside the inlet to Chatham Harbor.

State shark scientist Greg Skomal said harpooner Bill Chaprales of Cape Cod Shark Hunters speared a female great white shark that was over 15 feet, with some on the boat estimating it at 18 to 20 feet long.

"We won't know until we are able to see the aerials (photographs taken by the spotter plane)," Skomal said. At 15 feet, the female would probably weigh more than 1,500 pounds, he said.

Because of the loss of a major funding source this summer, the state's great white shark harpoon tagging effort with Cape Cod Shark Hunters fell far short of other years in terms of the number of trips and sharks tagged, with just four trips and two sharks. In total, Skomal and the Cape-based fishermen have tagged 36 sharks since 2009, including 20 last summer.

This summer Skomal also partnered with the private shark research organization OCEARCH, which brought a 126-foot vessel into Chatham waters, caught an additional two great whites and outfitted them with multiple tracking and data-gathering devices.

It appears someone may have stolen some of the specialized receivers that listen for the unique identifying signal given off by the acoustic tags. Three others appear to have been damaged by vessels. Each receiver costs about $1,500, and is anchored in relatively shallow water off the coastline from Chatham to Truro.

"Clearly someone has tampered with many of our receivers," Skomal said. Most were located between Nauset Beach in Orleans north to Truro. He estimated it would cost about $10,000 to replace them, and that those towns lost the information stored on the receivers.

The Atlantic White Shark Conservancy, a local nonprofit group created last year to help fill the funding gap in Skomal's research, raised enough money this summer to pay $1,800 for a spotter plane for one trip, and for the combined plane and boat for the three other trips at $3,500 each. They also bought 10 acoustic tags, costing $400 each, for Skomal to use.

"For us, it's a matter of doing what we can to support this shark research program," said conservancy Director Cynthia Wigren, who said the group had a great response from the community to the fundraising events they held this year.

"A huge piece (of next year's goal) will be funding as many trips as possible," she said.

Skomal said the prospect of deteriorating weather conditions and lack of money meant Thursday likely would be the final expedition of the season. He said they were able to increase the amount of information they get from each harpoon-tagged shark this year, by combining a satellite pop-up tag and an acoustic tag on each of the detachable harpoon heads that remain stuck in the dorsal fin after it is hit.

The pop-up tag will record information on location, depth and water temperature for months at a time, detaching itself at a pre-programmed date and downloading the data to a satellite when it surfaces. Acoustic tags can last for years and allow scientists to track sharks as they pass receivers set up along the coastline from Maine to Florida.

Researchers this fall also attempted to remove a tissue sample from each shark using a specialized hollow-tipped pole that punctured the skin and retrieved a thin core of flesh, like a biopsy sample. Scientists will use that sample for genetic analysis to test an ongoing theory that the Northwest Atlantic great white population is genetically distinct from that of other regions.

They also will use this genetic fingerprint as a way to identify the shark in the future and begin piecing together the lineage and familial connections of the great whites that inhabit the Atlantic.

Skomal's team also used an underwater camera to determine the sex of each shark and to make sure they weren't putting a device on one that had already been tagged.

Wigren said her organization would be looking at how to raise more money for next year's tagging effort, but was also starting a new online and newsletter campaign to engage students in shark research by connecting them with scientists.

"This shows that our organization was able to accomplish the goals we set, and the need for funding," Wigren said. "Hopefully, we proved ourselves in this first year and that we'll be able to grow."